Swimmer starting platform



FIG. 1 is an isometric view of a front, top, and left side of an ornamental design for a swimmer starting platform;

FIG. 2 is an isometric view of a rear, bottom, and left side of the swimmer starting platform of FIG. 1; and,

FIG. 3 is a right side elevational view of the swimmer starting platform of FIG. 1.

The broken lines are included for the purpose of illustrating environmental structure and form no part of the claimed design. 

CLAIM The ornamental design for a swimmer starting platform, as shown and described. 